The work Lichtbahnen (Zeit und Blende) : Paths of Light (Time and Aperture) deals with the principle of photography and the materialization of the process of taking a picture. In photography, exposure value denotes a calculated combination of time (camera shutter speed) and relative aperture. The white background paper represents time and the black, aperture. The micro controller, attached to two motors, makes a random selection from a set of computerized figures of time and aperture, which translates into the movement of the papers. The movements and intervals of the two papers refer to a combination of time and aperture as an exposure value.